To provide a sponsored story unit, the social networking system receives a story request from an advertiser. The story request specifies properties of content used to generate the sponsored story. When the social networking system stores an object or an action performed on an object, properties associated with, and describing, the object or the action are also stored. For example, properties of an object include an object type, an object identifier, metadata describing the object or other suitable information. The social networking system identifies actions or objects associated with users connected to a viewing user having one or more properties included in a story request. A sponsored story is generated from the identified actions or objects and presented to a viewing user.